Snail ID

[Nemo]

Dr. Ron,
First let me say we are very fortunate to have someone of your knowledge answering questions for us. I truely enjoyed hearing you speak at the CMAS sping symposium last year and hope to hear you at MACNA in Baltimore this summer.

My question is about a snail that I have started to see in my reef within the last year. I assume it hitchhiked in on a coral colony somewhere down the line. It's numbers have been slowly increasing yet I have seen no egg masses in the tank.

These snails are about 1-2mm in length when fully grown. Their shells are conical, elongated and come to a sharp point. I don't see any canal near the opening of the shell but they are so small I could miss seeing that. The shell coloration is snow white.

I find them on the shells of several different types of snails (trocus, margarita, nerite and astrea ). They are always found on the underside of the snails shell near their foot but not touching the actual foot. They appear to be eating mucus that is produced by the host snail itself or they could be secreting this mucus themselves. One possibility for not finding these snails on the exposed side of the snail is a neon dotty back which I have in the reef.

I have a large 12" Derasa clam that shows no ill effects of these snails. There are no bore holes and I have never seen these snails anywhere on the clam. A parasitic clam snail was my first guess.

I have not found any bore holes in my other snails or had any increase in snail mortality. These snails seem harmless so I have left them alone but kept a watch on them.

I realize that pictures of these snails would be a big help to you in identification but given their small size, I would be very difficult to get detailed pictures. I am just looking for a ballpark guess on these guys if possible.

Thank you for your time,

Nemo

[rshimek]

Hi Nemo,

Originally posted by Nemo
I truely enjoyed hearing you speak at the CMAS sping symposium last year and hope to hear you at MACNA in Baltimore this summer.

The CMAS symposium was indeed a good meeting! I have not been asked to speak at MACNA; consequently, I will not be there.

I find them on the shells of several different types of snails (trocus, margarita, nerite and astrea ). They are always found on the underside of the snails shell near their foot but not touching the actual foot. They appear to be eating mucus that is produced by the host snail itself or they could be secreting this mucus themselves.

Your description is sufficient to narrow down the snail's identity to one of two groups (the taxonomic Family Eulimidae or the Family Pyramidellidae). Unfortunately, both groups are parasitic. I suspect pretty strongly your snail is a pyram, as eulimids usually parasitize echinoderms such as sea cucumbers or urchins.

These animals will be sucking the hosts blood. They puncture the skin and insert a fine proboscis to suck out the blood.

One possibility for not finding these snails on the exposed side of the snail is a neon dotty back which I have in the reef.

This may well be eating the snails, but I suspect they are not on the exposed side of the snail simply because that is not where their food is.

I have a large 12" Derasa clam that shows no ill effects of these snails. There are no bore holes and I have never seen these snails anywhere on the clam. A parasitic clam snail was my first guess.

Close guess, they are parasitic on snails, and they tend to be host specific.

I have not found any bore holes in my other snails or had any increase in snail mortality.

No bore holes are necessary, and good parasites don't kill their host (otherwise they die).

I am just looking for a ballpark guess on these guys if possible.

If you want a more precise identification, you can collect a couple and mail them to me.



[Edited by rshimek on 01-21-2001 at 08:01 AM]

[Nemo]

Dr. Ron,
Thank you very much for the ID. I don't have very many of them in my tank so manual removal should not be a problem. Time to break out the tweezers.

Thanks,

Nemo